With increasing government demands on emission control systems and fuel mileage concerns, the power plant of a vehicle has become a high tech engineering marvel. This, in turn, means that the automotive technician is faced with increasing difficulties of diagnosing and repairing complicated systems. Repairs must be completed in a timely manner which has become a problem for many automotive repair shops.
The modern vehicle (1996 and later models) has a number of microprocessors including one programmed to control the running parameters of the power plant (i.e., the powertrain control module). The data from this microprocessor provides the skilled technician with information that is needed in order to make diagnostic decisions about the power plant. However, as the power plant systems become more complicated, more data and a better understanding of such data is needed in order to make accurate diagnostic decisions, thus making it more difficult for technicians to see a problem when it occurs. Even if available data is saved, a technician may overlook important information and can misdiagnose the system.
Definitions
Unless otherwise indicated (e.g., Volumetric efficiency tests which would work on diesel engines) Power Plant includes:                a gasoline engine (including engines which also run on alternate fuels, such as ethanol, either alone or mixed with gasoline);        powertrain control module (sometimes referred to by the acronym PCM or ECM (for engine control module));        engine control system (sensors, such as an O2 sensor, that feed data to the PCM and activators that carry out PCM commands, such as fuel injectors, exhaust gas recirculator, and purge control);        starting system, including starter motor and “key”;        charging system;        air induction system (e.g., air filter, MAS (mass airflow sensor; sometimes referred to by the acronym MAF);        fuel delivery system (e.g., fuel pump, fuel filter, fuel pressure regulator, fuel pressure sensor, fuel damper, injectors);        cooling system (e.g., radiator, water pump, thermostat); and        exhaust system.        
The foregoing are intended to be illustrative. As those skilled in the art will appreciate the above are not necessarily mutually exclusive or exhaustive categories. For instance, the air induction system includes the intake manifold which is generally considered part of the engine. Similarly, the fluid passages on the engine are part of the cooling system. Further, engines, depending on size, year of manufacture and manufacturer, have different control systems (e.g., different numbers and locations of O2 sensors). While all fuel delivery systems include a pump, fuel filter and injectors, not all include a fuel pressure sensor or a fuel damper. The term key, as used herein, includes any type of starting device, whether a traditional key and tumbler system, or a laser based or a frequency based device. Finally, unless otherwise indicated, the term vehicle is intended to cover gasoline engine powered vehicles, such as automobiles and light trucks. Other definitions (e.g., PID/PIDS; Paragraph [0011]) are set forth elsewhere in the specification.
Objects of the Invention
What was needed is a way in which the automotive technician can easily connect to the automobile's power train control module with a device that could help diagnose the power plant systems quickly and accurately.
It is an object of the present invention to provide an analysis tool that will interface with the power train control module and alert the technician to problems with, for instance, the engine control system as they occur, to permit the technician to zero in on such problems as they occur.
It is a further object of the present invention to provide an analysis tool with alert lights, whereby failures are brought to the attention of the technician as they occur.
Furthermore, it is an object of the present invention to provide an automated analysis tool to help a technician that does not have the technical skill level needed to make correct diagnostic decisions.